13 TCO 7 Explain why oxygen is critical to generation of ene

13. (TCO 7) Explain why oxygen is critical to generation of energy in a cell. Include details of the chemical reactions involved and where in the cell they occur.(Points : 10)

Solution

ATP is the energy currency of the cell and occurance of Electron transport chain in Mitochondrial inner membrane utilises oxygen as an electron acceptor, finally causes ATP synthesis

Diet we have taken in to the body undergo metabolosm and converted into simple, small molecules like glucose and entered into the cell.

In the cell it undergo oxidation and produce electron rich compounds like NADH & FADH2.

They have high tendency to donate electrons that means have high reduction potential value.

The reduction potential values of various components of electron transport chain are as follows: NADH OR FADH2>COMPLEX-1>UQ>COMPLEX-2>CYTOCHROME-C>COMPLEX-3>COMPLEX-4>OXYGEN

Due to high reduction potential, spontanious electron flow occur from NADH or FADH2 to oxygen

Here oxygen possess least reduction potential, so it readily accept electrons and make the electron transport chain (ETC) as an exergonic process.

The released energy of ETC pump the H+ ions from mitochondrial matrix to perimitochondrial membrane, where proton motive force generated. This proton motive force finally responsible for ATP synthesis

In this way Oxygen makes ETC as spontanious proces, promotes proton pumping, generates Proton motive force and finally responsible for ATP synthesis